/* $Id: tif_pixarlog.c,v 1.15.2.4 2010-06-08 18:50:42 bfriesen Exp $ */

/*
 * Copyright (c) 1996-1997 Sam Leffler
 * Copyright (c) 1996 Pixar
 *
 * Permission to use, copy, modify, distribute, and sell this software and 
 * its documentation for any purpose is hereby granted without fee, provided
 * that (i) the above copyright notices and this permission notice appear in
 * all copies of the software and related documentation, and (ii) the names of
 * Pixar, Sam Leffler and Silicon Graphics may not be used in any advertising or
 * publicity relating to the software without the specific, prior written
 * permission of Pixar, Sam Leffler and Silicon Graphics.
 * 
 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
 * 
 * IN NO EVENT SHALL PIXAR, SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 
 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
 * OF THIS SOFTWARE.
 */

#include "tiffiop.h"
#ifdef PIXARLOG_SUPPORT

/*
 * TIFF Library.
 * PixarLog Compression Support
 *
 * Contributed by Dan McCoy.
 *
 * PixarLog film support uses the TIFF library to store companded
 * 11 bit values into a tiff file, which are compressed using the 
 * zip compressor.  
 *
 * The codec can take as input and produce as output 32-bit IEEE float values 
 * as well as 16-bit or 8-bit unsigned integer values.
 *
 * On writing any of the above are converted into the internal
 * 11-bit log format.   In the case of  8 and 16 bit values, the
 * input is assumed to be unsigned linear color values that represent
 * the range 0-1.  In the case of IEEE values, the 0-1 range is assumed to
 * be the normal linear color range, in addition over 1 values are
 * accepted up to a value of about 25.0 to encode "hot" hightlights and such.
 * The encoding is lossless for 8-bit values, slightly lossy for the
 * other bit depths.  The actual color precision should be better
 * than the human eye can perceive with extra room to allow for
 * error introduced by further image computation.  As with any quantized
 * color format, it is possible to perform image calculations which
 * expose the quantization error. This format should certainly be less 
 * susceptable to such errors than standard 8-bit encodings, but more
 * susceptable than straight 16-bit or 32-bit encodings.
 *
 * On reading the internal format is converted to the desired output format.
 * The program can request which format it desires by setting the internal
 * pseudo tag TIFFTAG_PIXARLOGDATAFMT to one of these possible values:
 *  PIXARLOGDATAFMT_FLOAT     = provide IEEE float values.
 *  PIXARLOGDATAFMT_16BIT     = provide unsigned 16-bit integer values
 *  PIXARLOGDATAFMT_8BIT      = provide unsigned 8-bit integer values
 *
 * alternately PIXARLOGDATAFMT_8BITABGR provides unsigned 8-bit integer
 * values with the difference that if there are exactly three or four channels
 * (rgb or rgba) it swaps the channel order (bgr or abgr).
 *
 * PIXARLOGDATAFMT_11BITLOG provides the internal encoding directly
 * packed in 16-bit values.   However no tools are supplied for interpreting
 * these values.
 *
 * "hot" (over 1.0) areas written in floating point get clamped to
 * 1.0 in the integer data types.
 *
 * When the file is closed after writing, the bit depth and sample format
 * are set always to appear as if 8-bit data has been written into it.
 * That way a naive program unaware of the particulars of the encoding
 * gets the format it is most likely able to handle.
 *
 * The codec does it's own horizontal differencing step on the coded
 * values so the libraries predictor stuff should be turned off.
 * The codec also handle byte swapping the encoded values as necessary
 * since the library does not have the information necessary
 * to know the bit depth of the raw unencoded buffer.
 * 
 */

#include "tif_predict.h"
#include "zlib.h"

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

/* Tables for converting to/from 11 bit coded values */

#define  TSIZE     2048        /* decode table size (11-bit tokens) */
#define  TSIZEP1 2049        /* Plus one for slop */
#define  ONE     1250        /* token value of 1.0 exactly */
#define  RATIO     1.004        /* nominal ratio for log part */

#define CODE_MASK 0x7ff         /* 11 bits. */

static float  Fltsize;
static float  LogK1, LogK2;

#define REPEAT(n, op)   { int i; i=n; do { i--; op; } while (i>0); }

static void
horizontalAccumulateF(uint16 *wp, int n, int stride, float *op, 
    float *ToLinearF)
{
    unsigned int  cr, cg, cb, ca, mask;
    float  t0, t1, t2, t3;

    if (n >= stride) {
    mask = CODE_MASK;
    if (stride == 3) {
        t0 = ToLinearF[cr = wp[0]];
        t1 = ToLinearF[cg = wp[1]];
        t2 = ToLinearF[cb = wp[2]];
        op[0] = t0;
        op[1] = t1;
        op[2] = t2;
        n -= 3;
        while (n > 0) {
        wp += 3;
        op += 3;
        n -= 3;
        t0 = ToLinearF[(cr += wp[0]) & mask];
        t1 = ToLinearF[(cg += wp[1]) & mask];
        t2 = ToLinearF[(cb += wp[2]) & mask];
        op[0] = t0;
        op[1] = t1;
        op[2] = t2;
        }
    } else if (stride == 4) {
        t0 = ToLinearF[cr = wp[0]];
        t1 = ToLinearF[cg = wp[1]];
        t2 = ToLinearF[cb = wp[2]];
        t3 = ToLinearF[ca = wp[3]];
        op[0] = t0;
        op[1] = t1;
        op[2] = t2;
        op[3] = t3;
        n -= 4;
        while (n > 0) {
        wp += 4;
        op += 4;
        n -= 4;
        t0 = ToLinearF[(cr += wp[0]) & mask];
        t1 = ToLinearF[(cg += wp[1]) & mask];
        t2 = ToLinearF[(cb += wp[2]) & mask];
        t3 = ToLinearF[(ca += wp[3]) & mask];
        op[0] = t0;
        op[1] = t1;
        op[2] = t2;
        op[3] = t3;
        }
    } else {
        REPEAT(stride, *op = ToLinearF[*wp&mask]; wp++; op++)
        n -= stride;
        while (n > 0) {
        REPEAT(stride,
            wp[stride] += *wp; *op = ToLinearF[*wp&mask]; wp++; op++)
        n -= stride;
        }
    }
    }
}

static void
horizontalAccumulate12(uint16 *wp, int n, int stride, int16 *op,
    float *ToLinearF)
{
    unsigned int  cr, cg, cb, ca, mask;
    float  t0, t1, t2, t3;

#define SCALE12 2048.0F
#define CLAMP12(t) (((t) < 3071) ? (uint16) (t) : 3071)

    if (n >= stride) {
    mask = CODE_MASK;
    if (stride == 3) {
        t0 = ToLinearF[cr = wp[0]] * SCALE12;
        t1 = ToLinearF[cg = wp[1]] * SCALE12;
        t2 = ToLinearF[cb = wp[2]] * SCALE12;
        op[0] = CLAMP12(t0);
        op[1] = CLAMP12(t1);
        op[2] = CLAMP12(t2);
        n -= 3;
        while (n > 0) {
        wp += 3;
        op += 3;
        n -= 3;
        t0 = ToLinearF[(cr += wp[0]) & mask] * SCALE12;
        t1 = ToLinearF[(cg += wp[1]) & mask] * SCALE12;
        t2 = ToLinearF[(cb += wp[2]) & mask] * SCALE12;
        op[0] = CLAMP12(t0);
        op[1] = CLAMP12(t1);
        op[2] = CLAMP12(t2);
        }
    } else if (stride == 4) {
        t0 = ToLinearF[cr = wp[0]] * SCALE12;
        t1 = ToLinearF[cg = wp[1]] * SCALE12;
        t2 = ToLinearF[cb = wp[2]] * SCALE12;
        t3 = ToLinearF[ca = wp[3]] * SCALE12;
        op[0] = CLAMP12(t0);
        op[1] = CLAMP12(t1);
        op[2] = CLAMP12(t2);
        op[3] = CLAMP12(t3);
        n -= 4;
        while (n > 0) {
        wp += 4;
        op += 4;
        n -= 4;
        t0 = ToLinearF[(cr += wp[0]) & mask] * SCALE12;
        t1 = ToLinearF[(cg += wp[1]) & mask] * SCALE12;
        t2 = ToLinearF[(cb += wp[2]) & mask] * SCALE12;
        t3 = ToLinearF[(ca += wp[3]) & mask] * SCALE12;
        op[0] = CLAMP12(t0);
        op[1] = CLAMP12(t1);
        op[2] = CLAMP12(t2);
        op[3] = CLAMP12(t3);
        }
    } else {
        REPEAT(stride, t0 = ToLinearF[*wp&mask] * SCALE12;
                           *op = CLAMP12(t0); wp++; op++)
        n -= stride;
        while (n > 0) {
        REPEAT(stride,
            wp[stride] += *wp; t0 = ToLinearF[wp[stride]&mask]*SCALE12;
            *op = CLAMP12(t0);  wp++; op++)
        n -= stride;
        }
    }
    }
}

static void
horizontalAccumulate16(uint16 *wp, int n, int stride, uint16 *op,
    uint16 *ToLinear16)
{
    unsigned int  cr, cg, cb, ca, mask;

    if (n >= stride) {
    mask = CODE_MASK;
    if (stride == 3) {
        op[0] = ToLinear16[cr = wp[0]];
        op[1] = ToLinear16[cg = wp[1]];
        op[2] = ToLinear16[cb = wp[2]];
        n -= 3;
        while (n > 0) {
        wp += 3;
        op += 3;
        n -= 3;
        op[0] = ToLinear16[(cr += wp[0]) & mask];
        op[1] = ToLinear16[(cg += wp[1]) & mask];
        op[2] = ToLinear16[(cb += wp[2]) & mask];
        }
    } else if (stride == 4) {
        op[0] = ToLinear16[cr = wp[0]];
        op[1] = ToLinear16[cg = wp[1]];
        op[2] = ToLinear16[cb = wp[2]];
        op[3] = ToLinear16[ca = wp[3]];
        n -= 4;
        while (n > 0) {
        wp += 4;
        op += 4;
        n -= 4;
        op[0] = ToLinear16[(cr += wp[0]) & mask];
        op[1] = ToLinear16[(cg += wp[1]) & mask];
        op[2] = ToLinear16[(cb += wp[2]) & mask];
        op[3] = ToLinear16[(ca += wp[3]) & mask];
        }
    } else {
        REPEAT(stride, *op = ToLinear16[*wp&mask]; wp++; op++)
        n -= stride;
        while (n > 0) {
        REPEAT(stride,
            wp[stride] += *wp; *op = ToLinear16[*wp&mask]; wp++; op++)
        n -= stride;
        }
    }
    }
}

/* 
 * Returns the log encoded 11-bit values with the horizontal
 * differencing undone.
 */
static void
horizontalAccumulate11(uint16 *wp, int n, int stride, uint16 *op)
{
    unsigned int  cr, cg, cb, ca, mask;

    if (n >= stride) {
    mask = CODE_MASK;
    if (stride == 3) {
        op[0] = cr = wp[0];  op[1] = cg = wp[1];  op[2] = cb = wp[2];
        n -= 3;
        while (n > 0) {
        wp += 3;
        op += 3;
        n -= 3;
        op[0] = (cr += wp[0]) & mask;
        op[1] = (cg += wp[1]) & mask;
        op[2] = (cb += wp[2]) & mask;
        }
    } else if (stride == 4) {
        op[0] = cr = wp[0];  op[1] = cg = wp[1];
        op[2] = cb = wp[2];  op[3] = ca = wp[3];
        n -= 4;
        while (n > 0) {
        wp += 4;
        op += 4;
        n -= 4;
        op[0] = (cr += wp[0]) & mask;
        op[1] = (cg += wp[1]) & mask;
        op[2] = (cb += wp[2]) & mask;
        op[3] = (ca += wp[3]) & mask;
        } 
    } else {
        REPEAT(stride, *op = *wp&mask; wp++; op++)
        n -= stride;
        while (n > 0) {
        REPEAT(stride,
            wp[stride] += *wp; *op = *wp&mask; wp++; op++)
        n -= stride;
        }
    }
    }
}

static void
horizontalAccumulate8(uint16 *wp, int n, int stride, unsigned char *op,
    unsigned char *ToLinear8)
{
    unsigned int  cr, cg, cb, ca, mask;

    if (n >= stride) {
    mask = CODE_MASK;
    if (stride == 3) {
        op[0] = ToLinear8[cr = wp[0]];
        op[1] = ToLinear8[cg = wp[1]];
        op[2] = ToLinear8[cb = wp[2]];
        n -= 3;
        while (n > 0) {
        n -= 3;
        wp += 3;
        op += 3;
        op[0] = ToLinear8[(cr += wp[0]) & mask];
        op[1] = ToLinear8[(cg += wp[1]) & mask];
        op[2] = ToLinear8[(cb += wp[2]) & mask];
        }
    } else if (stride == 4) {
        op[0] = ToLinear8[cr = wp[0]];
        op[1] = ToLinear8[cg = wp[1]];
        op[2] = ToLinear8[cb = wp[2]];
        op[3] = ToLinear8[ca = wp[3]];
        n -= 4;
        while (n > 0) {
        n -= 4;
        wp += 4;
        op += 4;
        op[0] = ToLinear8[(cr += wp[0]) & mask];
        op[1] = ToLinear8[(cg += wp[1]) & mask];
        op[2] = ToLinear8[(cb += wp[2]) & mask];
        op[3] = ToLinear8[(ca += wp[3]) & mask];
        }
    } else {
        REPEAT(stride, *op = ToLinear8[*wp&mask]; wp++; op++)
        n -= stride;
        while (n > 0) {
        REPEAT(stride,
            wp[stride] += *wp; *op = ToLinear8[*wp&mask]; wp++; op++)
        n -= stride;
        }
    }
    }
}


static void
horizontalAccumulate8abgr(uint16 *wp, int n, int stride, unsigned char *op,
    unsigned char *ToLinear8)
{
    unsigned int  cr, cg, cb, ca, mask;
    unsigned char  t0, t1, t2, t3;

    if (n >= stride) {
    mask = CODE_MASK;
    if (stride == 3) {
        op[0] = 0;
        t1 = ToLinear8[cb = wp[2]];
        t2 = ToLinear8[cg = wp[1]];
        t3 = ToLinear8[cr = wp[0]];
        op[1] = t1;
        op[2] = t2;
        op[3] = t3;
        n -= 3;
        while (n > 0) {
        n -= 3;
        wp += 3;
        op += 4;
        op[0] = 0;
        t1 = ToLinear8[(cb += wp[2]) & mask];
        t2 = ToLinear8[(cg += wp[1]) & mask];
        t3 = ToLinear8[(cr += wp[0]) & mask];
        op[1] = t1;
        op[2] = t2;
        op[3] = t3;
        }
    } else if (stride == 4) {
        t0 = ToLinear8[ca = wp[3]];
        t1 = ToLinear8[cb = wp[2]];
        t2 = ToLinear8[cg = wp[1]];
        t3 = ToLinear8[cr = wp[0]];
        op[0] = t0;
        op[1] = t1;
        op[2] = t2;
        op[3] = t3;
        n -= 4;
        while (n > 0) {
        n -= 4;
        wp += 4;
        op += 4;
        t0 = ToLinear8[(ca += wp[3]) & mask];
        t1 = ToLinear8[(cb += wp[2]) & mask];
        t2 = ToLinear8[(cg += wp[1]) & mask];
        t3 = ToLinear8[(cr += wp[0]) & mask];
        op[0] = t0;
        op[1] = t1;
        op[2] = t2;
        op[3] = t3;
        }
    } else {
        REPEAT(stride, *op = ToLinear8[*wp&mask]; wp++; op++)
        n -= stride;
        while (n > 0) {
        REPEAT(stride,
            wp[stride] += *wp; *op = ToLinear8[*wp&mask]; wp++; op++)
        n -= stride;
        }
    }
    }
}

/*
 * State block for each open TIFF
 * file using PixarLog compression/decompression.
 */
typedef    struct {
    TIFFPredictorState    predict;
    z_stream        stream;
    uint16            *tbuf; 
    uint16            stride;
    int            state;
    int            user_datafmt;
    int            quality;
#define PLSTATE_INIT 1

    TIFFVSetMethod        vgetparent;    /* super-class method */
    TIFFVSetMethod        vsetparent;    /* super-class method */

    float *ToLinearF;
    uint16 *ToLinear16;
    unsigned char *ToLinear8;
    uint16  *FromLT2;
    uint16  *From14; /* Really for 16-bit data, but we shift down 2 */
    uint16  *From8;
    
} PixarLogState;

static int
PixarLogMakeTables(PixarLogState *sp)
{

/*
 *    We make several tables here to convert between various external
 *    representations (float, 16-bit, and 8-bit) and the internal
 *    11-bit companded representation.  The 11-bit representation has two
 *    distinct regions.  A linear bottom end up through .018316 in steps
 *    of about .000073, and a region of constant ratio up to about 25.
 *    These floating point numbers are stored in the main table ToLinearF. 
 *    All other tables are derived from this one.  The tables (and the
 *    ratios) are continuous at the internal seam.
 */

    int  nlin, lt2size;
    int  i, j;
    double  b, c, linstep, v;
    float *ToLinearF;
    uint16 *ToLinear16;
    unsigned char *ToLinear8;
    uint16  *FromLT2;
    uint16  *From14; /* Really for 16-bit data, but we shift down 2 */
    uint16  *From8;

    c = log(RATIO);    
    nlin = (int)(1./c);    /* nlin must be an integer */
    c = 1./nlin;
    b = exp(-c*ONE);    /* multiplicative scale factor [b*exp(c*ONE) = 1] */
    linstep = b*c*exp(1.);

    LogK1 = (float)(1./c);    /* if (v >= 2)  token = k1*log(v*k2) */
    LogK2 = (float)(1./b);
    lt2size = (int)(2./linstep) + 1;
    FromLT2 = (uint16 *)_TIFFmalloc(lt2size*sizeof(uint16));
    From14 = (uint16 *)_TIFFmalloc(16384*sizeof(uint16));
    From8 = (uint16 *)_TIFFmalloc(256*sizeof(uint16));
    ToLinearF = (float *)_TIFFmalloc(TSIZEP1 * sizeof(float));
    ToLinear16 = (uint16 *)_TIFFmalloc(TSIZEP1 * sizeof(uint16));
    ToLinear8 = (unsigned char *)_TIFFmalloc(TSIZEP1 * sizeof(unsigned char));
    if (FromLT2 == NULL || From14  == NULL || From8   == NULL ||
     ToLinearF == NULL || ToLinear16 == NULL || ToLinear8 == NULL) {
    if (FromLT2) _TIFFfree(FromLT2);
    if (From14) _TIFFfree(From14);
    if (From8) _TIFFfree(From8);
    if (ToLinearF) _TIFFfree(ToLinearF);
    if (ToLinear16) _TIFFfree(ToLinear16);
    if (ToLinear8) _TIFFfree(ToLinear8);
    sp->FromLT2 = NULL;
    sp->From14 = NULL;
    sp->From8 = NULL;
    sp->ToLinearF = NULL;
    sp->ToLinear16 = NULL;
    sp->ToLinear8 = NULL;
    return 0;
    }

    j = 0;

    for (i = 0; i < nlin; i++)  {
    v = i * linstep;
    ToLinearF[j++] = (float)v;
    }

    for (i = nlin; i < TSIZE; i++)
    ToLinearF[j++] = (float)(b*exp(c*i));

    ToLinearF[2048] = ToLinearF[2047];

    for (i = 0; i < TSIZEP1; i++)  {
    v = ToLinearF[i]*65535.0 + 0.5;
    ToLinear16[i] = (v > 65535.0) ? 65535 : (uint16)v;
    v = ToLinearF[i]*255.0  + 0.5;
    ToLinear8[i]  = (v > 255.0) ? 255 : (unsigned char)v;
    }

    j = 0;
    for (i = 0; i < lt2size; i++)  {
    if ((i*linstep)*(i*linstep) > ToLinearF[j]*ToLinearF[j+1])
        j++;
    FromLT2[i] = j;
    }

    /*
     * Since we lose info anyway on 16-bit data, we set up a 14-bit
     * table and shift 16-bit values down two bits on input.
     * saves a little table space.
     */
    j = 0;
    for (i = 0; i < 16384; i++)  {
    while ((i/16383.)*(i/16383.) > ToLinearF[j]*ToLinearF[j+1])
        j++;
    From14[i] = j;
    }

    j = 0;
    for (i = 0; i < 256; i++)  {
    while ((i/255.)*(i/255.) > ToLinearF[j]*ToLinearF[j+1])
        j++;
    From8[i] = j;
    }

    Fltsize = (float)(lt2size/2);

    sp->ToLinearF = ToLinearF;
    sp->ToLinear16 = ToLinear16;
    sp->ToLinear8 = ToLinear8;
    sp->FromLT2 = FromLT2;
    sp->From14 = From14;
    sp->From8 = From8;

    return 1;
}

#define    DecoderState(tif)    ((PixarLogState*) (tif)->tif_data)
#define    EncoderState(tif)    ((PixarLogState*) (tif)->tif_data)

static    int PixarLogEncode(TIFF*, tidata_t, tsize_t, tsample_t);
static    int PixarLogDecode(TIFF*, tidata_t, tsize_t, tsample_t);

#define PIXARLOGDATAFMT_UNKNOWN    -1

static int
PixarLogGuessDataFmt(TIFFDirectory *td)
{
    int guess = PIXARLOGDATAFMT_UNKNOWN;
    int format = td->td_sampleformat;

    /* If the user didn't tell us his datafmt,
     * take our best guess from the bitspersample.
     */
    switch (td->td_bitspersample) {
     case 32:
        if (format == SAMPLEFORMAT_IEEEFP)
            guess = PIXARLOGDATAFMT_FLOAT;
        break;
     case 16:
        if (format == SAMPLEFORMAT_VOID || format == SAMPLEFORMAT_UINT)
            guess = PIXARLOGDATAFMT_16BIT;
        break;
     case 12:
        if (format == SAMPLEFORMAT_VOID || format == SAMPLEFORMAT_INT)
            guess = PIXARLOGDATAFMT_12BITPICIO;
        break;
     case 11:
        if (format == SAMPLEFORMAT_VOID || format == SAMPLEFORMAT_UINT)
            guess = PIXARLOGDATAFMT_11BITLOG;
        break;
     case 8:
        if (format == SAMPLEFORMAT_VOID || format == SAMPLEFORMAT_UINT)
            guess = PIXARLOGDATAFMT_8BIT;
        break;
    }

    return guess;
}

static uint32
multiply(size_t m1, size_t m2)
{
    uint32    bytes = m1 * m2;

    if (m1 && bytes / m1 != m2)
        bytes = 0;

    return bytes;
}

static int
PixarLogSetupDecode(TIFF* tif)
{
    TIFFDirectory *td = &tif->tif_dir;
    PixarLogState* sp = DecoderState(tif);
    tsize_t tbuf_size;
    static const char module[] = "PixarLogSetupDecode";

    assert(sp != NULL);

    /* Make sure no byte swapping happens on the data
     * after decompression. */
    tif->tif_postdecode = _TIFFNoPostDecode;

    /* for some reason, we can't do this in TIFFInitPixarLog */

    sp->stride = (td->td_planarconfig == PLANARCONFIG_CONTIG ?
        td->td_samplesperpixel : 1);
    tbuf_size = multiply(multiply(multiply(sp->stride, td->td_imagewidth),
                      td->td_rowsperstrip), sizeof(uint16));
    if (tbuf_size == 0)
        return (0);
    sp->tbuf = (uint16 *) _TIFFmalloc(tbuf_size);
    if (sp->tbuf == NULL)
        return (0);
    if (sp->user_datafmt == PIXARLOGDATAFMT_UNKNOWN)
        sp->user_datafmt = PixarLogGuessDataFmt(td);
    if (sp->user_datafmt == PIXARLOGDATAFMT_UNKNOWN) {
        TIFFErrorExt(tif->tif_clientdata, module,
            "PixarLog compression can't handle bits depth/data format combination (depth: %d)", 
            td->td_bitspersample);
        return (0);
    }

    if (inflateInit(&sp->stream) != Z_OK) {
        TIFFErrorExt(tif->tif_clientdata, module, "%s: %s", tif->tif_name, sp->stream.msg);
        return (0);
    } else {
        sp->state |= PLSTATE_INIT;
        return (1);
    }
}

/*
 * Setup state for decoding a strip.
 */
static int
PixarLogPreDecode(TIFF* tif, tsample_t s)
{
    PixarLogState* sp = DecoderState(tif);

    (void) s;
    assert(sp != NULL);
    sp->stream.next_in = tif->tif_rawdata;
    sp->stream.avail_in = tif->tif_rawcc;
    return (inflateReset(&sp->stream) == Z_OK);
}

static int
PixarLogDecode(TIFF* tif, tidata_t op, tsize_t occ, tsample_t s)
{
    TIFFDirectory *td = &tif->tif_dir;
    PixarLogState* sp = DecoderState(tif);
    static const char module[] = "PixarLogDecode";
    int i, nsamples, llen;
    uint16 *up;

    switch (sp->user_datafmt) {
    case PIXARLOGDATAFMT_FLOAT:
        nsamples = occ / sizeof(float);    /* XXX float == 32 bits */
        break;
    case PIXARLOGDATAFMT_16BIT:
    case PIXARLOGDATAFMT_12BITPICIO:
    case PIXARLOGDATAFMT_11BITLOG:
        nsamples = occ / sizeof(uint16); /* XXX uint16 == 16 bits */
        break;
    case PIXARLOGDATAFMT_8BIT:
    case PIXARLOGDATAFMT_8BITABGR:
        nsamples = occ;
        break;
    default:
        TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
            "%d bit input not supported in PixarLog",
            td->td_bitspersample);
        return 0;
    }

    llen = sp->stride * td->td_imagewidth;

    (void) s;
    assert(sp != NULL);
    sp->stream.next_out = (unsigned char *) sp->tbuf;
    sp->stream.avail_out = nsamples * sizeof(uint16);
    do {
        int state = inflate(&sp->stream, Z_PARTIAL_FLUSH);
        if (state == Z_STREAM_END) {
            break;            /* XXX */
        }
        if (state == Z_DATA_ERROR) {
            TIFFErrorExt(tif->tif_clientdata, module,
                "%s: Decoding error at scanline %d, %s",
                tif->tif_name, tif->tif_row, sp->stream.msg);
            if (inflateSync(&sp->stream) != Z_OK)
                return (0);
            continue;
        }
        if (state != Z_OK) {
            TIFFErrorExt(tif->tif_clientdata, module, "%s: zlib error: %s",
                tif->tif_name, sp->stream.msg);
            return (0);
        }
    } while (sp->stream.avail_out > 0);

    /* hopefully, we got all the bytes we needed */
    if (sp->stream.avail_out != 0) {
        TIFFErrorExt(tif->tif_clientdata, module,
            "%s: Not enough data at scanline %d (short %d bytes)",
            tif->tif_name, tif->tif_row, sp->stream.avail_out);
        return (0);
    }

    up = sp->tbuf;
    /* Swap bytes in the data if from a different endian machine. */
    if (tif->tif_flags & TIFF_SWAB)
        TIFFSwabArrayOfShort(up, nsamples);

    /* 
     * if llen is not an exact multiple of nsamples, the decode operation
     * may overflow the output buffer, so truncate it enough to prevent
     * that but still salvage as much data as possible.
     */
    if (nsamples % llen) { 
        TIFFWarningExt(tif->tif_clientdata, module,
            "%s: stride %d is not a multiple of sample count, "
            "%d, data truncated.", tif->tif_name, llen, nsamples);
        nsamples -= nsamples % llen;
    }

    for (i = 0; i < nsamples; i += llen, up += llen) {
        switch (sp->user_datafmt)  {
        case PIXARLOGDATAFMT_FLOAT:
            horizontalAccumulateF(up, llen, sp->stride,
                    (float *)op, sp->ToLinearF);
            op += llen * sizeof(float);
            break;
        case PIXARLOGDATAFMT_16BIT:
            horizontalAccumulate16(up, llen, sp->stride,
                    (uint16 *)op, sp->ToLinear16);
            op += llen * sizeof(uint16);
            break;
        case PIXARLOGDATAFMT_12BITPICIO:
            horizontalAccumulate12(up, llen, sp->stride,
                    (int16 *)op, sp->ToLinearF);
            op += llen * sizeof(int16);
            break;
        case PIXARLOGDATAFMT_11BITLOG:
            horizontalAccumulate11(up, llen, sp->stride,
                    (uint16 *)op);
            op += llen * sizeof(uint16);
            break;
        case PIXARLOGDATAFMT_8BIT:
            horizontalAccumulate8(up, llen, sp->stride,
                    (unsigned char *)op, sp->ToLinear8);
            op += llen * sizeof(unsigned char);
            break;
        case PIXARLOGDATAFMT_8BITABGR:
            horizontalAccumulate8abgr(up, llen, sp->stride,
                    (unsigned char *)op, sp->ToLinear8);
            op += llen * sizeof(unsigned char);
            break;
        default:
            TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                  "PixarLogDecode: unsupported bits/sample: %d", 
                  td->td_bitspersample);
            return (0);
        }
    }

    return (1);
}

static int
PixarLogSetupEncode(TIFF* tif)
{
    TIFFDirectory *td = &tif->tif_dir;
    PixarLogState* sp = EncoderState(tif);
    tsize_t tbuf_size;
    static const char module[] = "PixarLogSetupEncode";

    assert(sp != NULL);

    /* for some reason, we can't do this in TIFFInitPixarLog */

    sp->stride = (td->td_planarconfig == PLANARCONFIG_CONTIG ?
        td->td_samplesperpixel : 1);
    tbuf_size = multiply(multiply(multiply(sp->stride, td->td_imagewidth),
                      td->td_rowsperstrip), sizeof(uint16));
    if (tbuf_size == 0)
        return (0);
    sp->tbuf = (uint16 *) _TIFFmalloc(tbuf_size);
    if (sp->tbuf == NULL)
        return (0);
    if (sp->user_datafmt == PIXARLOGDATAFMT_UNKNOWN)
        sp->user_datafmt = PixarLogGuessDataFmt(td);
    if (sp->user_datafmt == PIXARLOGDATAFMT_UNKNOWN) {
        TIFFErrorExt(tif->tif_clientdata, module, "PixarLog compression can't handle %d bit linear encodings", td->td_bitspersample);
        return (0);
    }

    if (deflateInit(&sp->stream, sp->quality) != Z_OK) {
        TIFFErrorExt(tif->tif_clientdata, module, "%s: %s", tif->tif_name, sp->stream.msg);
        return (0);
    } else {
        sp->state |= PLSTATE_INIT;
        return (1);
    }
}

/*
 * Reset encoding state at the start of a strip.
 */
static int
PixarLogPreEncode(TIFF* tif, tsample_t s)
{
    PixarLogState *sp = EncoderState(tif);

    (void) s;
    assert(sp != NULL);
    sp->stream.next_out = tif->tif_rawdata;
    sp->stream.avail_out = tif->tif_rawdatasize;
    return (deflateReset(&sp->stream) == Z_OK);
}

static void
horizontalDifferenceF(float *ip, int n, int stride, uint16 *wp, uint16 *FromLT2)
{

    int32 r1, g1, b1, a1, r2, g2, b2, a2, mask;
    float fltsize = Fltsize;

#define  CLAMP(v) ( (v<(float)0.)   ? 0                \
          : (v<(float)2.)   ? FromLT2[(int)(v*fltsize)]    \
          : (v>(float)24.2) ? 2047            \
          : LogK1*log(v*LogK2) + 0.5 )

    mask = CODE_MASK;
    if (n >= stride) {
    if (stride == 3) {
        r2 = wp[0] = (uint16) CLAMP(ip[0]);
        g2 = wp[1] = (uint16) CLAMP(ip[1]);
        b2 = wp[2] = (uint16) CLAMP(ip[2]);
        n -= 3;
        while (n > 0) {
        n -= 3;
        wp += 3;
        ip += 3;
        r1 = (int32) CLAMP(ip[0]); wp[0] = (r1-r2) & mask; r2 = r1;
        g1 = (int32) CLAMP(ip[1]); wp[1] = (g1-g2) & mask; g2 = g1;
        b1 = (int32) CLAMP(ip[2]); wp[2] = (b1-b2) & mask; b2 = b1;
        }
    } else if (stride == 4) {
        r2 = wp[0] = (uint16) CLAMP(ip[0]);
        g2 = wp[1] = (uint16) CLAMP(ip[1]);
        b2 = wp[2] = (uint16) CLAMP(ip[2]);
        a2 = wp[3] = (uint16) CLAMP(ip[3]);
        n -= 4;
        while (n > 0) {
        n -= 4;
        wp += 4;
        ip += 4;
        r1 = (int32) CLAMP(ip[0]); wp[0] = (r1-r2) & mask; r2 = r1;
        g1 = (int32) CLAMP(ip[1]); wp[1] = (g1-g2) & mask; g2 = g1;
        b1 = (int32) CLAMP(ip[2]); wp[2] = (b1-b2) & mask; b2 = b1;
        a1 = (int32) CLAMP(ip[3]); wp[3] = (a1-a2) & mask; a2 = a1;
        }
    } else {
        ip += n - 1;    /* point to last one */
        wp += n - 1;    /* point to last one */
        n -= stride;
        while (n > 0) {
        REPEAT(stride, wp[0] = (uint16) CLAMP(ip[0]);
                wp[stride] -= wp[0];
                wp[stride] &= mask;
                wp--; ip--)
        n -= stride;
        }
        REPEAT(stride, wp[0] = (uint16) CLAMP(ip[0]); wp--; ip--)
    }
    }
}

static void
horizontalDifference16(unsigned short *ip, int n, int stride, 
    unsigned short *wp, uint16 *From14)
{
    int  r1, g1, b1, a1, r2, g2, b2, a2, mask;

/* assumption is unsigned pixel values */
#undef   CLAMP
#define  CLAMP(v) From14[(v) >> 2]

    mask = CODE_MASK;
    if (n >= stride) {
    if (stride == 3) {
        r2 = wp[0] = CLAMP(ip[0]);  g2 = wp[1] = CLAMP(ip[1]);
        b2 = wp[2] = CLAMP(ip[2]);
        n -= 3;
        while (n > 0) {
        n -= 3;
        wp += 3;
        ip += 3;
        r1 = CLAMP(ip[0]); wp[0] = (r1-r2) & mask; r2 = r1;
        g1 = CLAMP(ip[1]); wp[1] = (g1-g2) & mask; g2 = g1;
        b1 = CLAMP(ip[2]); wp[2] = (b1-b2) & mask; b2 = b1;
        }
    } else if (stride == 4) {
        r2 = wp[0] = CLAMP(ip[0]);  g2 = wp[1] = CLAMP(ip[1]);
        b2 = wp[2] = CLAMP(ip[2]);  a2 = wp[3] = CLAMP(ip[3]);
        n -= 4;
        while (n > 0) {
        n -= 4;
        wp += 4;
        ip += 4;
        r1 = CLAMP(ip[0]); wp[0] = (r1-r2) & mask; r2 = r1;
        g1 = CLAMP(ip[1]); wp[1] = (g1-g2) & mask; g2 = g1;
        b1 = CLAMP(ip[2]); wp[2] = (b1-b2) & mask; b2 = b1;
        a1 = CLAMP(ip[3]); wp[3] = (a1-a2) & mask; a2 = a1;
        }
    } else {
        ip += n - 1;    /* point to last one */
        wp += n - 1;    /* point to last one */
        n -= stride;
        while (n > 0) {
        REPEAT(stride, wp[0] = CLAMP(ip[0]);
                wp[stride] -= wp[0];
                wp[stride] &= mask;
                wp--; ip--)
        n -= stride;
        }
        REPEAT(stride, wp[0] = CLAMP(ip[0]); wp--; ip--)
    }
    }
}


static void
horizontalDifference8(unsigned char *ip, int n, int stride, 
    unsigned short *wp, uint16 *From8)
{
    int  r1, g1, b1, a1, r2, g2, b2, a2, mask;

#undef     CLAMP
#define  CLAMP(v) (From8[(v)])

    mask = CODE_MASK;
    if (n >= stride) {
    if (stride == 3) {
        r2 = wp[0] = CLAMP(ip[0]);  g2 = wp[1] = CLAMP(ip[1]);
        b2 = wp[2] = CLAMP(ip[2]);
        n -= 3;
        while (n > 0) {
        n -= 3;
        r1 = CLAMP(ip[3]); wp[3] = (r1-r2) & mask; r2 = r1;
        g1 = CLAMP(ip[4]); wp[4] = (g1-g2) & mask; g2 = g1;
        b1 = CLAMP(ip[5]); wp[5] = (b1-b2) & mask; b2 = b1;
        wp += 3;
        ip += 3;
        }
    } else if (stride == 4) {
        r2 = wp[0] = CLAMP(ip[0]);  g2 = wp[1] = CLAMP(ip[1]);
        b2 = wp[2] = CLAMP(ip[2]);  a2 = wp[3] = CLAMP(ip[3]);
        n -= 4;
        while (n > 0) {
        n -= 4;
        r1 = CLAMP(ip[4]); wp[4] = (r1-r2) & mask; r2 = r1;
        g1 = CLAMP(ip[5]); wp[5] = (g1-g2) & mask; g2 = g1;
        b1 = CLAMP(ip[6]); wp[6] = (b1-b2) & mask; b2 = b1;
        a1 = CLAMP(ip[7]); wp[7] = (a1-a2) & mask; a2 = a1;
        wp += 4;
        ip += 4;
        }
    } else {
        wp += n + stride - 1;    /* point to last one */
        ip += n + stride - 1;    /* point to last one */
        n -= stride;
        while (n > 0) {
        REPEAT(stride, wp[0] = CLAMP(ip[0]);
                wp[stride] -= wp[0];
                wp[stride] &= mask;
                wp--; ip--)
        n -= stride;
        }
        REPEAT(stride, wp[0] = CLAMP(ip[0]); wp--; ip--)
    }
    }
}

/*
 * Encode a chunk of pixels.
 */
static int
PixarLogEncode(TIFF* tif, tidata_t bp, tsize_t cc, tsample_t s)
{
    TIFFDirectory *td = &tif->tif_dir;
    PixarLogState *sp = EncoderState(tif);
    static const char module[] = "PixarLogEncode";
    int    i, n, llen;
    unsigned short * up;

    (void) s;

    switch (sp->user_datafmt) {
    case PIXARLOGDATAFMT_FLOAT:
        n = cc / sizeof(float);        /* XXX float == 32 bits */
        break;
    case PIXARLOGDATAFMT_16BIT:
    case PIXARLOGDATAFMT_12BITPICIO:
    case PIXARLOGDATAFMT_11BITLOG:
        n = cc / sizeof(uint16);    /* XXX uint16 == 16 bits */
        break;
    case PIXARLOGDATAFMT_8BIT:
    case PIXARLOGDATAFMT_8BITABGR:
        n = cc;
        break;
    default:
        TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
            "%d bit input not supported in PixarLog",
            td->td_bitspersample);
        return 0;
    }

    llen = sp->stride * td->td_imagewidth;

    for (i = 0, up = sp->tbuf; i < n; i += llen, up += llen) {
        switch (sp->user_datafmt)  {
        case PIXARLOGDATAFMT_FLOAT:
            horizontalDifferenceF((float *)bp, llen, 
                sp->stride, up, sp->FromLT2);
            bp += llen * sizeof(float);
            break;
        case PIXARLOGDATAFMT_16BIT:
            horizontalDifference16((uint16 *)bp, llen, 
                sp->stride, up, sp->From14);
            bp += llen * sizeof(uint16);
            break;
        case PIXARLOGDATAFMT_8BIT:
            horizontalDifference8((unsigned char *)bp, llen, 
                sp->stride, up, sp->From8);
            bp += llen * sizeof(unsigned char);
            break;
        default:
            TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                "%d bit input not supported in PixarLog",
                td->td_bitspersample);
            return 0;
        }
    }
 
    sp->stream.next_in = (unsigned char *) sp->tbuf;
    sp->stream.avail_in = n * sizeof(uint16);

    do {
        if (deflate(&sp->stream, Z_NO_FLUSH) != Z_OK) {
            TIFFErrorExt(tif->tif_clientdata, module, "%s: Encoder error: %s",
                tif->tif_name, sp->stream.msg);
            return (0);
        }
        if (sp->stream.avail_out == 0) {
            tif->tif_rawcc = tif->tif_rawdatasize;
            TIFFFlushData1(tif);
            sp->stream.next_out = tif->tif_rawdata;
            sp->stream.avail_out = tif->tif_rawdatasize;
        }
    } while (sp->stream.avail_in > 0);
    return (1);
}

/*
 * Finish off an encoded strip by flushing the last
 * string and tacking on an End Of Information code.
 */

static int
PixarLogPostEncode(TIFF* tif)
{
    PixarLogState *sp = EncoderState(tif);
    static const char module[] = "PixarLogPostEncode";
    int state;

    sp->stream.avail_in = 0;

    do {
        state = deflate(&sp->stream, Z_FINISH);
        switch (state) {
        case Z_STREAM_END:
        case Z_OK:
            if (sp->stream.avail_out != (uint32)tif->tif_rawdatasize) {
                tif->tif_rawcc =
                tif->tif_rawdatasize - sp->stream.avail_out;
                TIFFFlushData1(tif);
                sp->stream.next_out = tif->tif_rawdata;
                sp->stream.avail_out = tif->tif_rawdatasize;
            }
            break;
        default:
            TIFFErrorExt(tif->tif_clientdata, module, "%s: zlib error: %s",
            tif->tif_name, sp->stream.msg);
            return (0);
        }
    } while (state != Z_STREAM_END);
    return (1);
}

static void
PixarLogClose(TIFF* tif)
{
    TIFFDirectory *td = &tif->tif_dir;

    /* In a really sneaky maneuver, on close, we covertly modify both
     * bitspersample and sampleformat in the directory to indicate
     * 8-bit linear.  This way, the decode "just works" even for
     * readers that don't know about PixarLog, or how to set
     * the PIXARLOGDATFMT pseudo-tag.
     */
    td->td_bitspersample = 8;
    td->td_sampleformat = SAMPLEFORMAT_UINT;
}

static void
PixarLogCleanup(TIFF* tif)
{
    PixarLogState* sp = (PixarLogState*) tif->tif_data;

    assert(sp != 0);

    (void)TIFFPredictorCleanup(tif);

    tif->tif_tagmethods.vgetfield = sp->vgetparent;
    tif->tif_tagmethods.vsetfield = sp->vsetparent;

    if (sp->FromLT2) _TIFFfree(sp->FromLT2);
    if (sp->From14) _TIFFfree(sp->From14);
    if (sp->From8) _TIFFfree(sp->From8);
    if (sp->ToLinearF) _TIFFfree(sp->ToLinearF);
    if (sp->ToLinear16) _TIFFfree(sp->ToLinear16);
    if (sp->ToLinear8) _TIFFfree(sp->ToLinear8);
    if (sp->state&PLSTATE_INIT) {
        if (tif->tif_mode == O_RDONLY)
            inflateEnd(&sp->stream);
        else
            deflateEnd(&sp->stream);
    }
    if (sp->tbuf)
        _TIFFfree(sp->tbuf);
    _TIFFfree(sp);
    tif->tif_data = NULL;

    _TIFFSetDefaultCompressionState(tif);
}

static int
PixarLogVSetField(TIFF* tif, ttag_t tag, va_list ap)
{
    PixarLogState *sp = (PixarLogState *)tif->tif_data;
    int result;
    static const char module[] = "PixarLogVSetField";

    switch (tag) {
     case TIFFTAG_PIXARLOGQUALITY:
        sp->quality = va_arg(ap, int);
        if (tif->tif_mode != O_RDONLY && (sp->state&PLSTATE_INIT)) {
            if (deflateParams(&sp->stream,
                sp->quality, Z_DEFAULT_STRATEGY) != Z_OK) {
                TIFFErrorExt(tif->tif_clientdata, module, "%s: zlib error: %s",
                    tif->tif_name, sp->stream.msg);
                return (0);
            }
        }
        return (1);
     case TIFFTAG_PIXARLOGDATAFMT:
    sp->user_datafmt = va_arg(ap, int);
    /* Tweak the TIFF header so that the rest of libtiff knows what
     * size of data will be passed between app and library, and
     * assume that the app knows what it is doing and is not
     * confused by these header manipulations...
     */
    switch (sp->user_datafmt) {
     case PIXARLOGDATAFMT_8BIT:
     case PIXARLOGDATAFMT_8BITABGR:
        TIFFSetField(tif, TIFFTAG_BITSPERSAMPLE, 8);
        TIFFSetField(tif, TIFFTAG_SAMPLEFORMAT, SAMPLEFORMAT_UINT);
        break;
     case PIXARLOGDATAFMT_11BITLOG:
        TIFFSetField(tif, TIFFTAG_BITSPERSAMPLE, 16);
        TIFFSetField(tif, TIFFTAG_SAMPLEFORMAT, SAMPLEFORMAT_UINT);
        break;
     case PIXARLOGDATAFMT_12BITPICIO:
        TIFFSetField(tif, TIFFTAG_BITSPERSAMPLE, 16);
        TIFFSetField(tif, TIFFTAG_SAMPLEFORMAT, SAMPLEFORMAT_INT);
        break;
     case PIXARLOGDATAFMT_16BIT:
        TIFFSetField(tif, TIFFTAG_BITSPERSAMPLE, 16);
        TIFFSetField(tif, TIFFTAG_SAMPLEFORMAT, SAMPLEFORMAT_UINT);
        break;
     case PIXARLOGDATAFMT_FLOAT:
        TIFFSetField(tif, TIFFTAG_BITSPERSAMPLE, 32);
        TIFFSetField(tif, TIFFTAG_SAMPLEFORMAT, SAMPLEFORMAT_IEEEFP);
        break;
    }
    /*
     * Must recalculate sizes should bits/sample change.
     */
    tif->tif_tilesize = isTiled(tif) ? TIFFTileSize(tif) : (tsize_t) -1;
    tif->tif_scanlinesize = TIFFScanlineSize(tif);
    result = 1;        /* NB: pseudo tag */
    break;
     default:
    result = (*sp->vsetparent)(tif, tag, ap);
    }
    return (result);
}

static int
PixarLogVGetField(TIFF* tif, ttag_t tag, va_list ap)
{
    PixarLogState *sp = (PixarLogState *)tif->tif_data;

    switch (tag) {
     case TIFFTAG_PIXARLOGQUALITY:
    *va_arg(ap, int*) = sp->quality;
    break;
     case TIFFTAG_PIXARLOGDATAFMT:
    *va_arg(ap, int*) = sp->user_datafmt;
    break;
     default:
    return (*sp->vgetparent)(tif, tag, ap);
    }
    return (1);
}

static const TIFFFieldInfo pixarlogFieldInfo[] = {
    {TIFFTAG_PIXARLOGDATAFMT,0,0,TIFF_ANY,  FIELD_PSEUDO,FALSE,FALSE,""},
    {TIFFTAG_PIXARLOGQUALITY,0,0,TIFF_ANY,  FIELD_PSEUDO,FALSE,FALSE,""}
};

int
TIFFInitPixarLog(TIFF* tif, int scheme)
{
    static const char module[] = "TIFFInitPixarLog";

    PixarLogState* sp;

    assert(scheme == COMPRESSION_PIXARLOG);

    /*
     * Merge codec-specific tag information.
     */
    if (!_TIFFMergeFieldInfo(tif, pixarlogFieldInfo,
                 TIFFArrayCount(pixarlogFieldInfo))) {
        TIFFErrorExt(tif->tif_clientdata, module,
                 "Merging PixarLog codec-specific tags failed");
        return 0;
    }

    /*
     * Allocate state block so tag methods have storage to record values.
     */
    tif->tif_data = (tidata_t) _TIFFmalloc(sizeof (PixarLogState));
    if (tif->tif_data == NULL)
        goto bad;
    sp = (PixarLogState*) tif->tif_data;
    _TIFFmemset(sp, 0, sizeof (*sp));
    sp->stream.data_type = Z_BINARY;
    sp->user_datafmt = PIXARLOGDATAFMT_UNKNOWN;

    /*
     * Install codec methods.
     */
    tif->tif_setupdecode = PixarLogSetupDecode;
    tif->tif_predecode = PixarLogPreDecode;
    tif->tif_decoderow = PixarLogDecode;
    tif->tif_decodestrip = PixarLogDecode;
    tif->tif_decodetile = PixarLogDecode;
    tif->tif_setupencode = PixarLogSetupEncode;
    tif->tif_preencode = PixarLogPreEncode;
    tif->tif_postencode = PixarLogPostEncode;
    tif->tif_encoderow = PixarLogEncode;
    tif->tif_encodestrip = PixarLogEncode;
    tif->tif_encodetile = PixarLogEncode;
    tif->tif_close = PixarLogClose;
    tif->tif_cleanup = PixarLogCleanup;

    /* Override SetField so we can handle our private pseudo-tag */
    sp->vgetparent = tif->tif_tagmethods.vgetfield;
    tif->tif_tagmethods.vgetfield = PixarLogVGetField;   /* hook for codec tags */
    sp->vsetparent = tif->tif_tagmethods.vsetfield;
    tif->tif_tagmethods.vsetfield = PixarLogVSetField;   /* hook for codec tags */

    /* Default values for codec-specific fields */
    sp->quality = Z_DEFAULT_COMPRESSION; /* default comp. level */
    sp->state = 0;

    /* we don't wish to use the predictor, 
     * the default is none, which predictor value 1
     */
    (void) TIFFPredictorInit(tif);

    /*
     * build the companding tables 
     */
    PixarLogMakeTables(sp);

    return (1);
bad:
    TIFFErrorExt(tif->tif_clientdata, module,
             "No space for PixarLog state block");
    return (0);
}
#endif /* PIXARLOG_SUPPORT */

/* vim: set ts=8 sts=8 sw=8 noet: */
/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 8
 * fill-column: 78
 * End:
 */
